WO2018096782A1

WO2018096782A1 - Vehicle clutch control device and vehicle clutch control method

Info

Publication number: WO2018096782A1
Application number: PCT/JP2017/035110
Authority: WO
Inventors: 弘一小辻; 拓朗平野; 徹浦沢
Original assignee: ジヤトコ株式会社; 日産自動車株式会社
Priority date: 2016-11-24
Filing date: 2017-09-28
Publication date: 2018-05-31
Also published as: JP2020029865A

Abstract

In the present invention, a transmission controller (12) sets a forward clutch (7b) for a belt-type continuously variable transmission (1) provided on the downstream side of a torque converter (6) to a disengaged state or a slipped state and increases the rotation of an engine (5) and the torque converter (6), and once the engine torque has exceeded a torque determined by the square of a torque capacity coefficient (τ) and an engine rotation speed (Ne), the transmission controller increases the fastening force of the forward clutch (7b) and transmits the rotation energy of the torque converter (6) and the engine (5) having increased rotation to a drive wheel (50), thereby increasing the acceleration generated in the vehicle (100).

Description

Vehicle clutch control device and vehicle clutch control method

The present invention relates to a vehicle clutch control device and a vehicle clutch control method.

Patent Document 1 discloses a technique for reducing a turbo lag at the start of a vehicle by controlling a fastening force of a pump clutch provided between an engine and a torque converter.

However, the technique of Patent Document 1 has a problem that the cost is increased by providing a pump clutch, and the axial dimension around the engine increases.

Therefore, in order to solve this problem, the present applicant has proposed Japanese Patent Application No. 2016-045271. However, in this proposal, after reaching a predetermined engine rotation, the fastening force of the clutch for the automatic transmission arranged downstream of the torque converter is increased, but the rotation of the turbine of the torque converter decreases. As a result, the torque converter capacity (engine load) increases, and therefore engine torque becomes insufficient due to engine variations and the like, which may cause a drop in engine rotation.

The present invention has been made in view of such a technical problem, and while suppressing an increase in cost and an increase in axial dimension around the engine, a decrease in engine rotation speed due to an increase in clutch engagement force is suppressed, The object is to improve the acceleration feeling when the vehicle starts.

JP 2007-170664 A

In the vehicle clutch control device and the vehicle clutch control method according to the present invention, after the engine torque exceeds the torque determined by the square of the capacity coefficient of the torque converter and the engine rotational speed, an increase in clutch engagement force is started. did.

Therefore, in the vehicle clutch control device and the vehicle clutch control method of the present invention, while suppressing an increase in cost and an increase in axial dimension around the engine, a decrease in engine rotation speed due to an increase in clutch engagement force is suppressed, Acceleration feeling when starting the vehicle can be improved.

1 is a schematic configuration diagram of a vehicle according to a first embodiment. 3 is a flowchart showing the contents of processing executed by the transmission controller of the first embodiment. 3 is a flowchart showing the contents of a clutch control process according to the first embodiment. It is the time chart which showed a mode that the clutch control of Example 1 was performed. It is a figure which shows the change of the turbine torque of Example 1, and a clutch capacity | capacitance. It is the flowchart which showed the content of the process which the transmission controller of Example 2 performs. It is the time chart which showed a mode that the clutch control of Example 2 was performed.

[Example 1]
Embodiment 1 of the present invention will be described below with reference to FIGS.

FIG. 1 is a schematic configuration diagram of a vehicle 100 according to a first embodiment of the present invention. As shown in FIG. 1, a vehicle 100 includes an engine 5, a belt-type continuously variable transmission (hereinafter referred to as “CVT”) 1 that changes the rotation of the engine 5 and transmits it to drive wheels 50, and an engine 5. A torque converter 6 provided between the CVT 1 and the CVT 1. The engine 5 includes a supercharger 21, and the torque converter 6 includes a lockup clutch 6c.

The CVT 1 is an automatic transmission including a forward / reverse switching mechanism 7 as a clutch for an automatic transmission, and a primary pulley 2 and a secondary pulley 3 that are torque transmission members are arranged so that their V grooves are aligned. A V-belt 4 is stretched around the V-grooves of the pulleys 2 and 3. An engine 5 is arranged coaxially with the primary pulley 2, and a torque converter 6 and a forward / reverse switching mechanism 7 are provided between the engine 5 and the primary pulley 2 in order from the engine 5 side.

The forward / reverse switching mechanism 7 includes a double pinion planetary gear set 7a as a main component, and its sun gear is coupled to the engine 5 via the torque converter 6 and the carrier is coupled to the primary pulley 2. The forward / reverse switching mechanism 7 further includes a forward clutch 7b that directly connects the sun gear and the carrier of the double pinion planetary gear set 7a, and a reverse brake 7c that fixes the ring gear. When the forward clutch 7b is engaged, the input rotation from the engine 5 via the torque converter 6 is directly transmitted to the primary pulley 2, and when the reverse brake 7c is engaged, the input rotation via the torque converter 6 from the engine 5 is reversed. Is transmitted to the primary pulley 2.

The rotation of the primary pulley 2 is transmitted to the secondary pulley 3 via the V belt 4, and the rotation of the secondary pulley 3 is transmitted to the drive wheel 50 through the output shaft 8, the gear set 9 and the differential gear device 10.

In order to make it possible to change the gear ratio between the primary pulley 2 and the secondary pulley 3 during the power transmission, one of the conical plates forming the V-grooves of the primary pulley 2 and the secondary pulley 3 is fixed to the fixed conical plates 2a, 3a. The other

conical plates

2b and 3b are movable conical plates that can be displaced in the axial direction.

These movable

conical plates

2b and 3b are directed toward the fixed conical plates 2a and 3a by supplying the primary pulley pressure Pp and the secondary pulley pressure Ps created using the line pressure as the original pressure to the primary pulley chamber 2c and the secondary pulley chamber 3c. As a result, the V-belt 4 is frictionally engaged with the conical plate, and power is transmitted between the primary pulley 2 and the secondary pulley 3.

At the time of shifting, the width of the V groove of both pulleys 2 and 3 is changed by the differential pressure between the primary pulley pressure Pp and the secondary pulley pressure Ps generated corresponding to the target gear ratio, and the V belt 4 with respect to the pulleys 2 and 3 is changed. The target gear ratio is realized by continuously changing the wrapping arc diameter.

The primary pulley pressure Pp and the secondary pulley pressure Ps are controlled by the shift control hydraulic circuit 11 together with the engagement hydraulic pressure of the forward clutch 7b that is engaged when the forward travel mode is selected and the reverse brake 7c that is engaged when the reverse travel mode is selected. The shift control hydraulic circuit 11 performs control in response to a signal from the transmission controller 12.

The transmission controller 12 includes a signal from the turbine rotation sensor 20 that detects the rotation speed Nt (turbine rotation Nt) of the output shaft 8 of the torque converter 6, and a primary pulley rotation sensor 13 that detects the rotation speed Np of the primary pulley 2. , A signal from the secondary pulley rotation sensor 14 that detects the rotational speed Ns of the secondary pulley 3, a signal from the secondary pulley pressure sensor 15 that detects the secondary pulley pressure Ps, and an accelerator that detects the accelerator opening APO. An engine controller for controlling the engine 5, a signal from the operation amount sensor 16, a selection mode signal from the select switch 17 for selecting the operation mode of the CVT 1, a signal from the oil temperature sensor 18 for detecting the oil temperature TMP of the

CVT

1, 19 is a signal related to the engine torque Te And Jin rotational speed Ne and the fuel injection time, etc.), the angle of the vehicle 100, i.e. a signal from the angle sensor 22 for detecting the gradient of the road surface, it is input.

Incidentally, as described above, since the engine 5 of the first embodiment includes the supercharger 21, the vehicle 100 may not have the acceleration feeling desired by the driver due to the occurrence of a turbo lag when starting. For this reason, the transmission controller 12 performs control for improving the feeling of acceleration felt by the driver when starting.

Specifically, when the vehicle 100 starts, the transmission controller 12 sets the forward clutch 7b of the forward / reverse switching mechanism 7 serving as an automatic transmission clutch in a slip state to increase the rotation of the engine 5 and the torque converter 6, After the engine torque Te based on the signal related to the engine torque Te from the controller 19 exceeds the torque determined by the square of the capacity coefficient τ of the torque converter 6 and the engine rotational speed Ne, the engagement force of the forward clutch 7b is increased to cause rotation. Control (hereinafter referred to as clutch control) for transmitting the increased rotational energy of the engine 5 and the torque converter 6 to the drive wheels 50 is performed. This will be described in more detail later.

On the other hand, there are cases where it is better not to start by clutch control, for example, when the driver has selected a fuel consumption mode that places importance on fuel consumption as the driving mode of CVT1. Therefore, the transmission controller 12 determines whether to start by clutch control or to perform normal start without clutch control according to the flowchart of FIG.

Hereinafter, processing executed by the transmission controller 12 will be described with reference to the flowchart of FIG.

The transmission controller 12 starts processing when the accelerator is turned from ON to OFF.

In step S11, the transmission controller 12 determines whether the vehicle speed is equal to or lower than a predetermined vehicle speed. The vehicle speed is calculated based on a signal from the secondary pulley rotation sensor 14.

If the transmission controller 12 determines that the vehicle speed is equal to or lower than the predetermined vehicle speed, the process proceeds to step S12. If it is determined that the vehicle speed is higher than the predetermined vehicle speed, the process proceeds to step S18.

The predetermined vehicle speed is, for example, 5 km / h, and is a vehicle speed at which the vehicle 100 is considered to stop as it is. In a state where the vehicle 100 is traveling, the driver can obtain an acceleration feeling at the start without performing clutch control. Therefore, when the vehicle speed is higher than the predetermined vehicle speed, the transmission controller 12 performs a normal start when the accelerator is turned from OFF to ON (Step S18, Step S19).

In step S12, the transmission controller 12 determines whether the oil temperature TMP of the CVT 1 is within the reference range based on the signal from the oil temperature sensor 18.

If the transmission controller 12 determines that the oil temperature TMP is within the reference range, the process proceeds to step S13. If it is determined that the oil temperature TMP is not within the reference range, the process proceeds to step S18, and normal start is performed when the accelerator is turned from OFF to ON (step S18, step S19). Specifically, the transmission controller 12 determines that the oil temperature TMP is in the low temperature region where the oil temperature TMP is equal to or lower than the first reference temperature and the oil temperature TMP is in the high temperature region where the oil temperature TMP is equal to or higher than the second reference temperature. If it is determined that it is not within the reference range, the process proceeds to step S18. When the oil temperature TMP is in the low temperature region, the controllability of the forward clutch 7b is lowered. Therefore, in this case, the certainty of control is ensured by prohibiting clutch control and performing normal start. The first reference temperature is 20 ° C., for example. Further, when the oil temperature TMP is in the high temperature region, it is considered that the forward clutch 7b is overheated when the clutch control is performed. Therefore, in this case, the forward clutch 7b is protected by prohibiting the clutch control and performing a normal start. The second reference temperature is 70 ° C., for example.

In step S13, the transmission controller 12 determines whether the ascending slope of the road surface is equal to or less than the reference angle based on the signal from the angle sensor 22.

When the transmission controller 12 determines that the road slope is equal to or smaller than the reference angle, the process proceeds to step S14. If it is determined that the road slope is larger than the reference angle, the process proceeds to step S18. When the accelerator is switched from OFF to ON, a normal start is performed (step S18, step S19). In the case of uphill traveling where the slope of the road surface is larger than the reference angle, it is conceivable that the vehicle 100 moves backward when clutch control is performed. Therefore, in this case, the vehicle 100 is prevented from moving backward by prohibiting the clutch control and performing a normal start. Note that the reference angle is, for example, 5 degrees.

In step S14, the transmission controller 12 determines whether the travel mode of the CVT 1 selected by the select switch 17 is the fuel consumption mode.

When the transmission controller 12 determines that the travel mode of the CVT 1 is the fuel consumption mode, the transmission controller 12 proceeds to step S18, and performs normal start when the accelerator is turned from OFF to ON (step S18, step S19). If it is determined that the travel mode of CVT1 is not the fuel efficiency mode, the process proceeds to step S15. When the fuel consumption mode is selected as the travel mode of CVT1, it is considered that the driver attaches more importance to the fuel consumption than the feeling of acceleration. Therefore, in this case, the fuel consumption is improved by prohibiting the clutch control and performing a normal start.

In step S15, the transmission controller 12 performs standby control to bring the forward clutch 7b into a slip state, and then starts by clutch control when the accelerator is turned from OFF to ON (step S16, step S17).

As described above, the standby control is executed on the assumption that the clutch control is always performed when starting. Therefore, in Example 1, when it is better not to perform clutch control, standby control and clutch control are prohibited by the above processing.

Hereinafter, the process in which the transmission controller 12 executes the clutch control in step S17 will be described in detail with reference to the flowchart of FIG.

When the transmission controller 12 enters the clutch control in step S17 of FIG. 2, it starts the clutch control process.

In step S21, the transmission controller 12 determines whether or not the engine torque Te exceeds the torque (τ * Ne ² ) calculated by multiplying the capacity coefficient τ of the torque converter 6 and the square of the engine rotational speed Ne. (Te> τ * Ne ² ). That is, even if the fastening pressure of the forward clutch 7b of the forward / reverse switching mechanism 7 as the automatic transmission clutch in the forward travel mode is increased to a predetermined value, that is, the capacity Tc of the forward clutch 7b is increased to a predetermined value. In addition, it is confirmed whether or not an engine torque Te that can withstand this load is generated.

If the transmission controller 12 determines that the engine torque Te exceeds the torque (τ * Ne ² ) calculated by multiplying the capacity coefficient τ of the torque converter 6 and the square of the engine speed Ne, the process proceeds to step S22. Transition. If it is determined that the engine torque Te does not exceed the torque (τ * Ne ² ) calculated by multiplying the capacity coefficient τ of the torque converter 6 and the square of the engine speed Ne, the process of step S21 is repeated. .

In step S22, the transmission controller 12 increases the engagement pressure of the forward clutch 7b of the forward / reverse switching mechanism 7 as the automatic transmission clutch in the forward travel mode to a predetermined value, that is, the capacity Tc of the forward clutch 7b is predetermined. The capacity is increased to the capacity Ttg01 and maintained.

In step S23, the transmission controller 12 obtains a torque (t * τ * Ne ² + ΔT) obtained by adding a torque step tolerance ΔT, which is a predetermined torque, to the turbine torque Tt (torque ratio t * capacity coefficient τ * Ne ² ). Then, it is determined whether or not the current capacity Ttg01 of the forward clutch 7b has been exceeded (Ttg01 <t * τ * Ne ² + ΔT).

The transmission controller 12 determines that the torque (t * τ * Ne ² + ΔT) obtained by adding a torque step tolerance ΔT, which is a predetermined torque, to the turbine torque Tt (torque ratio t * capacity coefficient τ * Ne ² ) If it is determined that the capacity Ttg01 of the clutch 7b has been exceeded, the process proceeds to step S24. The capacity Tc of the forward clutch 7b is greater than the turbine torque Tt by adding the inertia of the forward clutch 7b in addition to the turbine torque Tt that is input. Control is performed so that the torque for the inertia is suppressed to an allowable value ΔT or less. Further, a torque (t * τ * Ne ² + ΔT) obtained by adding a torque step tolerance ΔT, which is a predetermined torque, to the turbine torque Tt (torque ratio t * capacity coefficient τ * Ne ² ) is a current capacity of the forward clutch 7b. If it is determined that it does not exceed Ttg01, the process of step S23 is repeated.

In step S24, the transmission controller 12 sets the clutch engagement pressure of the forward clutch 7b of the forward / reverse switching mechanism 7 as the automatic transmission clutch to the capacity Tc of the forward clutch 7b and the turbine torque Tt (torque ratio t * capacity coefficient τ). * Ne ² ) is increased so that a torque (t * τ * Ne ² + ΔT) obtained by adding a torque step tolerance ΔT, which is a predetermined torque, matches.

In step S25, the transmission controller 12 determines whether or not the differential rotation before and after the forward clutch 7b of the forward / reverse switching mechanism 7 (the difference between the turbine rotation Nt and the rotation speed Np of the primary pulley 2) is equal to or less than a certain value ΔN. (Nt−Np ≦ ΔN).

When the transmission controller 12 determines that the forward / backward differential rotation (the difference between the turbine rotation Nt and the rotation speed Np of the primary pulley 2) of the forward clutch 7b of the forward / reverse switching mechanism 7 is equal to or less than a predetermined value ΔN, the transmission controller 12 starts the start by clutch control. End and shift to normal control. If it is determined that the forward / backward differential rotation (difference between the turbine rotation Nt and the rotation speed Np of the primary pulley 2) of the forward / reverse switching mechanism 7 is not equal to or less than a certain value ΔN, the process of step S25 is repeated.

Next, how the standby control and the clutch control are executed will be described based on the time chart shown in FIG. 4 in comparison with the case of the start by the comparative example (prior application) and the case of the start by the first embodiment. FIG. 5 is a graph showing changes in turbine torque Tt and clutch capacity in the first embodiment.

Before time t1, the accelerator is OFF and the vehicle 100 is stopped. Further, the forward travel mode is selected as the mode of CVT1, and the forward clutch 7b is in the slip state (standby control). Therefore, the rotation speed Np of the primary pulley 2 is zero, and the engine rotation speed Ne and the turbine rotation Nt rotate at a predetermined rotation difference by the amount of slip generated in the torque converter 6.

At time t2, when the accelerator is turned from OFF to ON, clutch control is started immediately. The forward clutch 7b maintains the slip state (standby control).

When the engine torque Te exceeds the torque (τ * Ne ² ) calculated by multiplying the capacity coefficient τ of the torque converter 6 and the square of the engine rotational speed Ne at time t3, the automatic transmission for the forward transmission mode is used. The engagement pressure of the forward clutch 7b of the forward / reverse switching mechanism 7 as a clutch is increased to a predetermined value, that is, the capacity Tc of the forward clutch 7b is increased to a predetermined capacity Ttg01, and this is maintained after time t4. On the other hand, in the comparative example, the time t3 ′, which is the starting point for increasing the engagement pressure of the forward clutch 7b, is determined based on the predetermined engine speed Ne, and after the time t4 ′ is increased rapidly to the predetermined pressure, the forward clutch Since the engagement pressure of 7b is gradually increased, the engine load increases due to the decrease in turbine rotation Nt due to the increase in capacity of the forward clutch 7b, and the engine speed Ne is determined only by the engine rotation speed Ne. It can be seen that there is a case where the torque Te is not sufficiently secured, a drop in the engine rotational speed Ne occurs, and the rapid increase in vehicle acceleration is hindered.

At time t5, the torque (t * τ * Ne ² + ΔT) obtained by adding the torque step tolerance ΔT, which is a predetermined torque, to the turbine torque Tt (torque ratio t * capacity coefficient τ * Ne ² ) is the current forward clutch 7b. When the capacity Ttg01 of the forward / reverse switching mechanism 7 is exceeded, the engagement pressure of the forward clutch 7b of the forward / reverse switching mechanism 7 is set to a torque step that is a predetermined torque between the capacity Tc of the forward clutch 7b and the turbine torque Tt (torque ratio t * capacity coefficient τ * Ne ² ) Is increased so that the torque (t * τ * Ne ² + ΔT) obtained by adding the allowable value ΔT of the two values coincides. At time t6, when the forward / backward differential rotation of the forward clutch 7b of the forward / reverse switching mechanism 7 (difference between the turbine rotation Nt and the rotational speed Np of the primary pulley 2) becomes equal to or less than a certain value ΔN, the forward clutch of the forward / reverse switching mechanism 7 The fastening pressure of 7b is increased to the full fastening pressure. At this time, a step corresponding to the allowable value ΔT of the torque step is generated in the vehicle acceleration, but since it is within the allowable value, it can be suppressed that the occupant feels a shock. On the other hand, in the comparative example, the clutch capacity Tc and the turbine torque Tt (torque ratio t * capacity coefficient τ * Ne ² ) have a torque difference of an allowable value ΔT or more, so that a large step occurs in the vehicle acceleration, which is inconvenient for the passenger. Gives pleasure.

Next, the function and effect will be described. The clutch control device for the vehicle 100 and the clutch control method for the vehicle 100 according to the first embodiment have the following effects.

(1) When the vehicle 100 starts, the forward clutch 7b for the CVT 1 serving as an automatic transmission is slipped to increase the rotation of the engine 5 and the torque converter 6, and the engine torque Te is determined by the capacity coefficient τ of the torque converter 6 and the engine rotation. After exceeding the torque determined by the square of the speed Ne, an increase in the fastening force of the forward clutch 7b of the forward / reverse switching mechanism 7 is started, and the rotational energy of the engine 5 and the torque converter 6 whose rotation has increased is supplied to the drive wheels 50. This is transmitted to increase the acceleration generated in the vehicle 100. Therefore, even if the engine load increases due to the turbine rotation Nt decreasing due to the increase in the capacity of the forward clutch 7b, the necessary engine torque Te is sufficiently secured, so that the engine rotation speed Ne does not drop, and the vehicle The acceleration generated in 100 can be rapidly increased, and the acceleration feeling felt by the driver can be improved. Further, since the rotation of the engine 5 and the torque converter 6 is increased using the forward clutch 7b of the CVT 1, it is possible to improve the feeling of acceleration when starting the vehicle while suppressing an increase in cost and an increase in the axial dimension around the engine.

(2) The increased clutch engagement force is maintained at the predetermined value until the torque obtained by adding the predetermined torque to the turbine torque Tt exceeds the capacity Tc of the forward clutch 7b. That is, the torque (t * τ * Ne ² + ΔT) obtained by adding the torque step tolerance ΔT, which is the predetermined torque, to the turbine torque Tt (torque ratio t * capacity coefficient τ * Ne ² ) is used as the capacity Tc of the forward clutch 7b. The capacity Tc of the forward clutch 7b is maintained at a predetermined value Ttg01 until it exceeds. Therefore, since the capacity of the forward clutch 7b is maintained at the predetermined value Ttg01, the engine speed Ne can be rapidly increased, the acceleration generated in the vehicle 100 can be increased, and the acceleration feeling felt by the driver can be increased. It can be improved.

(3) If the torque obtained by adding the predetermined torque to the turbine torque Tt exceeds the capacity Tc of the forward clutch 7b after maintaining the increased capacity Tc of the forward clutch 7b at the predetermined value Ttg01, the capacity Tc of the forward clutch 7b The capacity Tc of the forward clutch 7b is increased so that the torque obtained by adding the allowable value ΔT to the turbine torque Tt is obtained. Therefore, at this time, a step between the turbine torque Tt at the time of complete engagement and the capacity Tc of the forward clutch 7b, that is, a step corresponding to the allowable value ΔT occurs in the vehicle acceleration, but it can be suppressed that the passenger feels a shock because it is within the allowable value.

(4) By the standby control, the forward clutch 7b is in a slip state before the vehicle 100 stops. Therefore, the clutch control can be quickly started when the vehicle 100 starts.

(5) The transmission controller 12 prohibits the clutch control when the oil temperature TMP of the CVT 1 is in the low temperature region below the first reference temperature. Therefore, certainty of control can be ensured.

(6) The transmission controller 12 prohibits the clutch control when the oil temperature TMP of the CVT 1 is in a high temperature range equal to or higher than the second reference temperature. Therefore, the forward clutch 7b can be prevented from overheating, and the forward clutch 7b can be protected.

(7) The transmission controller 12 prohibits clutch control when the vehicle is traveling uphill where the road gradient is larger than the reference angle. Therefore, it is possible to prevent the vehicle 100 from moving backward when starting.

(8) The transmission controller 12 prohibits clutch control when the fuel economy mode in which the fuel efficiency is emphasized is selected as the driving mode of the CVT 1. Therefore, the fuel consumption can be improved.

(9) The engine 5 is an engine with a supercharger 21. Therefore, although turbo lag is generated when the vehicle starts, even a vehicle equipped with such a supercharger can improve the feeling of acceleration when starting.

[Example 2]
FIG. 6 is a flowchart showing the contents of processing executed by the transmission controller 12 of the second embodiment, and FIG. 7 is a time chart showing how the clutch control of the second embodiment is executed.

The transmission controller 12 starts processing when the accelerator is turned from OFF to ON.

In step S31, the transmission controller 12 determines whether a predetermined time has elapsed since the accelerator was turned on.

If the transmission controller 12 determines that a predetermined time has elapsed since the accelerator was turned on, the process proceeds to step S32. If it is determined that the predetermined time has not elapsed since the accelerator was turned on, the process of step S31 is repeated.

In step S32, the transmission controller 12 determines whether the accelerator opening APO is greater than or equal to the reference opening.

If the transmission controller 12 determines that the accelerator opening APO is greater than or equal to the reference opening, the process proceeds to step S33. If it is determined that the accelerator opening APO is less than the reference opening, the process proceeds to step S37 and a normal start is performed.

If the accelerator opening APO after a predetermined time has elapsed after the accelerator is turned on is less than the reference opening, it is considered that the driver does not intend to accelerate the vehicle 100 and is slowly depressing the accelerator. Therefore, in this case, the fuel consumption is improved by prohibiting the clutch control and performing a normal start. In addition, the predetermined time of step S31 is 0.3 sec, for example, and the reference opening degree of step S32 is 70%, for example.

In step S33, the transmission controller 12 determines whether the oil temperature TMP of the CVT 1 is within the reference range based on the signal from the oil temperature sensor 18.

If the transmission controller 12 determines that the oil temperature TMP is within the reference range, the process proceeds to step S34. If it is determined that the oil temperature TMP is not within the reference range, the process proceeds to step S37 and a normal start is performed.

In step S34, the transmission controller 12 determines whether the ascending slope of the road surface is equal to or less than the reference angle based on the signal from the angle sensor 22.

If the transmission controller 12 determines that the road slope is equal to or smaller than the reference angle, the process proceeds to step S35. If it is determined that the road slope is larger than the reference angle, the process proceeds to step S37 and a normal start is performed.

In step S35, the transmission controller 12 determines whether the travel mode of the CVT 1 selected by the select switch 17 is the fuel consumption mode.

If the transmission controller 12 determines that the travel mode of the CVT 1 is the fuel consumption mode, the transmission controller 12 proceeds to step S37 and performs normal start. If it is determined that the travel mode of CVT1 is not the fuel consumption mode, the process proceeds to step S36, and the vehicle starts with clutch control.

Next, the manner in which clutch control is executed will be described with reference to the time chart shown in FIG.

Prior to time t1, the accelerator is OFF and the vehicle 100 is stopped. Further, the forward travel mode is selected as the mode of CVT1, and the forward clutch 7b is completely engaged. For this reason, the rotational speed Nt of the output shaft 8 of the torque converter 6 and the rotational speed Np of the primary pulley 2 of the CVT 1 are zero.

When the accelerator is turned on at time t1, clutch control is started at time t2 when a predetermined time has elapsed, and the fastening force of the forward clutch 7b decreases. The predetermined time is, for example, 0.3 sec.

Since the forward clutch 7b is provided downstream of the torque converter 6 in the power transmission path, the fluid of the torque converter 6 is agitated out of the torque generated by the engine 5 when the forward clutch 7b is slipped. This reduces the torque used.

For this reason, in the case of starting by clutch control, the torque used for increasing the rotation of the engine 5 itself is increased and the increase in the engine speed Ne is higher than in the case of normal starting in which the forward clutch 7b starts with the engaged state. Promoted.

Thus, for example, at time t3, which is the elapsed time since the accelerator is turned on, in the case of starting by clutch control, the engine speed Ne is increased. Further, as can be seen from the change in the rotational speed Nt, the rotational speed of the torque converter 6 is also greatly increased.

At time t3, when the engine torque Te exceeds the torque (τ * Ne ² ) calculated by multiplying the capacity coefficient τ of the torque converter 6 and the square of the engine speed Ne, the automatic shift in the forward travel mode is performed. The fastening pressure of the forward clutch 7b of the forward / reverse switching mechanism 7 as a mechanical clutch is increased to a predetermined value, that is, the capacity Tc of the forward clutch 7b is increased to a predetermined capacity Ttg01, and this is maintained after time t4.

At time t5, the torque (t * τ * Ne ² + ΔT) obtained by adding the torque step tolerance ΔT, which is a predetermined torque, to the turbine torque Tt (torque ratio t * capacity coefficient τ * Ne ² ) is the current forward clutch 7b. Exceeding the capacity Ttg01, the engagement pressure of the forward clutch 7b of the forward / reverse switching mechanism 7 is set to a torque step where the capacity Tc of the forward clutch 7b is a predetermined torque to the turbine torque Tt (torque ratio t * capacity coefficient τ * Ne ² ). To the torque (t * τ * Ne ² + ΔT) obtained by adding the allowable value ΔT. At time t6, when the forward / backward differential rotation of the forward clutch 7b of the forward / reverse switching mechanism 7 (difference between the turbine rotation Nt and the rotational speed Np of the primary pulley 2) becomes equal to or less than a certain value ΔN, the forward clutch of the forward / reverse switching mechanism 7 The fastening pressure of 7b is increased to the full fastening pressure. At this time, a step corresponding to the allowable value ΔT occurs in the vehicle acceleration, but it can be suppressed that the passenger feels because it is within the allowable value.

Therefore, the second embodiment has the following operational effects in addition to the operational effects of the first embodiment except for standby control.

(1) The transmission controller 12 prohibits clutch control when the accelerator opening APO is equal to or less than the reference opening after a predetermined time has elapsed since the accelerator was turned on. In this case, it is considered that the driver does not intend to accelerate the vehicle 100. Therefore, fuel efficiency can be improved by performing normal start.

[Other embodiments]
As mentioned above, although the form for implementing this invention was demonstrated based on the Example, the concrete structure of this invention is not limited to the structure shown in the Example, and is the range which does not deviate from the summary of invention. Any design changes are included in the present invention.

For example, in the embodiment, in the clutch control, the engine speed Ne is increased by making the forward clutch 7b slip, but the forward clutch 7b may be in a released state. Also in the standby control of the first embodiment, the forward clutch 7b may be in a released state.

In the embodiment, standby control and clutch control are performed using the forward clutch 7b. However, if the power transmission path from the engine 5 to the drive wheels 50 is provided on the downstream side of the torque converter 6, the forward clutch A clutch other than 7b may be used.

In the embodiment, the present invention is applied to the vehicle 100 including the supercharger 21, but the present invention may be applied to a vehicle not including the supercharger.

In the embodiment, the automatic transmission provided in the vehicle 100 is CVT1, but the automatic transmission may be a stepped transmission.

Claims

An engine, an automatic transmission that shifts the rotation of the engine and transmits it to drive wheels, a torque converter provided between the engine and the automatic transmission, and the automatic provided downstream of the torque converter A vehicle clutch control device including a transmission clutch,
When the vehicle starts, the clutch for the automatic transmission is released or slipped to increase the rotation of the engine and the torque converter, and the engine torque is determined by the square of the capacity coefficient of the torque converter and the engine rotation speed. After the torque is exceeded, an increase in the engagement force of the clutch for the automatic transmission is started to transmit the rotational energy of the engine and the torque converter whose rotation has increased to the drive wheels, and the acceleration generated in the vehicle Rise,
Vehicle clutch control device.
The vehicle clutch control device according to claim 1,
Maintaining the capacity of the clutch with the increased fastening force at a predetermined capacity until the torque obtained by adding the predetermined torque to the turbine torque exceeds the capacity of the clutch;
Vehicle clutch control device.
The vehicle clutch control device according to claim 2,
After the torque obtained by adding the predetermined torque to the turbine torque exceeds the clutch capacity, the clutch capacity is increased to the turbine torque and the predetermined torque is maintained. To increase the engagement force of the clutch to increase the capacity of the clutch so that the torque obtained by adding
Vehicle clutch control device.
An engine, an automatic transmission that shifts the rotation of the engine and transmits it to drive wheels, a torque converter provided between the engine and the automatic transmission, and the automatic provided downstream of the torque converter A clutch control method for a vehicle including a clutch for a transmission,
When the vehicle starts, the clutch for the automatic transmission is released or slipped to increase the rotation of the engine and the torque converter, and the engine torque is determined by the square of the capacity coefficient of the torque converter and the engine rotation speed. After the torque is exceeded, an increase in the engagement force of the clutch for the automatic transmission is started to transmit the rotational energy of the engine and the torque converter whose rotation has increased to the drive wheels, and the acceleration generated in the vehicle Rise,
Vehicle clutch control method.
The vehicle clutch control method according to claim 4,
Maintaining the capacity of the clutch with the increased fastening force at a predetermined capacity until the torque obtained by adding the predetermined torque to the turbine torque exceeds the capacity of the clutch;
Vehicle clutch control method.
The vehicle clutch control method according to claim 5,
After the torque obtained by adding the predetermined torque to the turbine torque exceeds the clutch capacity, the clutch capacity is increased to the turbine torque and the predetermined torque is maintained. To increase the engagement force of the clutch to increase the capacity of the clutch so that the torque obtained by adding
Vehicle clutch control method.